It is known in vehicle seats in rear rows of seats that a backrest is mounted pivotably on the vehicle body by means of a simple fitting system and is locked with the vehicle body by means of a lock contained in the fitting system. A fitting system of the type mentioned in the introduction is known by use, in which a lock is provided on only one side of the vehicle seat, for example, on the lower part of the fitting, which is then locked on the opposing element, for example, a bolt (or a strap) on the upper part of the fitting.